Compression pump



F. s. CARVER.

COMPRESSION PUMP.

APPLICATION HLED'JUNE :8, 191a.

1,41 9,22 1 n Patented June 13,1922.

3 SHEETS-SHEET L ATTO RNEYS F; S. CARVER.

COMPRESSION PUMP. APPLICATION FILED JUNE 18, I9I 8.

1,419,221, Patented June 13,1922.-

3 SHEETS-SHEET 2.

F.S.CARVER.

COMPRESSION PUMP.

APPLICATION FILED JUNE 18, I918.

1,41 9 ,22 1 Patented June 13, 1922.

a SHEETSSHEET a.

\fih#" I 11 1 l5 1' L i g 7 I II 1#*. (On Line 455% 4) 47 INVENTOR 0011 ATTORNEYS FTAFE event FEEDS. CARVER, NEV ARK, NEN' JERSEY.

COMPRESSION PUMP.

iaiasai.

To all whom it may concern Be it known that l, FRED S. CARVER, a citizen of the United States, and a resident of Newark, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Compression Pumps, of which the following aspecification.

'My invention relates .to pumps for compressing fluid, such as air. One important field for use of a high duty pump in accordance with the present invention is in the compression of air for filling pneumatic tires of motor vehicles. For example, many of the heavy automobile trucks now used are equipped with pneumatic tires having a cross-sectional diameter as high as twelve inches or more and designed for garrying air pressures which may be as high as 150 pounds per square inch or even higher. A compression pump in accordance with my invention is well adapted for supplying air for filling such tires to the required high pressure, and is, of course, also adapted for other uses where efficient compression of fluid, such as air, is desired.

With the foregoing and related objects in view, my invention consists in the parts, improvements, and combinations herein set forth and claimed.

In the accompanying drawings in which.

the same reference numerals are uniformly applied to designate the same parts throughout, Figure 1 is a central, vertical, cross sectional view of a pump embodying the invention, such sectional view being taken substantially on the line 11, Figure 2, and also on line A B E F of Figure 41:. Figure 2 is an end View of the pump of Figure 1, and Figure 3 is a side view thereof. Figure 1 is a transverse sectional view taken in the neighborhood of the upper end. of the pump cylinders and substantially on the line 4 1, Figure 1. Figure 5 is a transverse sectional view taken in the neighborhood of the lower end of the pump cylinders and substantially on the line 5 5, Figure 1. Figure 6 is a transverse sectional view taken on a plane beneath the lower ends of the pump cylinders and substantially on line 6-G, Figure 1. Figure 7 is a vertical sectional view taken substantially on the broken line A B G H. Figure 4:. Figure 8 is a vertical. sectional view taken substantially on the broken line A B C E F, Figure at. Figure 9 is a vertical sectional view taken substan- Specification of Letters Patent. Patented J 13 192% Application filed June 18, 1918.

Serial No. 240,629.

tially on the broken line A B C D, Figure 1. Figure 10 is a vertical sectional view taken substantially on the broken line A B G- E F, Figure 4. Figure 11 is a detail sectional view of a preferred form, of check valve on its seat, and Figure 12 is a plan view of the check valve shown in Figure 11.

The pump of the present invention is preferably of the type involving the use of a multiplicity of cylinders, the lower pressure cylinders discharging into the higher pressure cylinders. In the form shown a singlelow pressure and a single high pressure cylinder are illustrated, the low pressure cylinder being designated at 10 and the high pressure cylinder at 11. Such cylinders are preferably formed side by side in a block casting 12 by boring from the upper end thereof, leaving a substantially plane upper surface as indicated at 13, the air passages being preferably suitably formed in the casting 12 as will hereinafter be described. The piston rods 11 and 15 of the pistons 16 and 17 project upwardly beyond the member 12. The pistons are preferably constructed of metal, as cast iron, and are provided with compression rings, as 16, 17'. A plurality of rings in separate grooves may be provided as shown in Figures 7 to 10, or two or more rings may be placed in a single groove, as shown in F igure 1, or the rings may be arranged in other ways.

The drive mechanism is preferably l0- cated above the cylinders, and in the form shown a second block member, preferably a casting 1.8, is provided and is suitablysecured to the member 12 as by a series of bolts 19 passing through flanges 20 and 21 on .the members 18 and 12. A suitable gasket may be provided between the memhere 12 and 18, if desired, so as to secure an air-tight connection. Openings are pro vided in the lower wall 22 of the member 18 for the passage of the piston rods 14 and 15, and in the form shown uawardly extending bosses 23, 23 are provide for receiving openings 241,25 for the piston rods, and suitable packing means are provided, in the form shown oppositely tapered preferably metallic packing rings 26 being utilized and the same are secured in place as by means of screw rings 27, 27. The openings 24 and 25 in the bosses 23, 23, and the openings in the screw rings 27, 27, are preferably made sufficiently large to give fairly substantial clearance about the piston rods so that the piston rods may have, to some extent, a floating action therein, the packing rings readily adjusting themselves thereto.

The driving means in the form shown comprises a shaft 28 carrying a cam or eccentric 29 which rotates in the preferably substantially elliptical opening 30 in a frame or Scotch yoke member 31 to which the pisston rods 14- and 15 are firmly secured as by being screwed and pinned therein, such screw-threaded connection being indicated at 32, 32. The upper ends of the piston rods preferably have a driving fit in sockets provided therefor in the member 31 and may be forced in by being screwed home and pen manently secured in place, as by pins or rivets, so that the machine part or element comprising the frame 31 and piston rods 1st and 15 forms a rigid substantially unitary structure which need never be taken apart and when worn to an extent requiring replacement, may be renewed as a whole. Said frame 31, which is adapted to be vertically reciprocated by the eccentric 29 and to impart vertically reciprocating movement to the pistons 16 and 17, is preferably provided with means for guiding and steadying its movement in the casting or other member 18, and in the form shown such member 31 has laterally projecting shoulders 34-, 34: formed thereon and with outer plane faces adapted to bear against and be guided by suitably formed. and preferably elongated guide-ways 33, 33 provided on the inner walls of the casting 18, and extending on each side of the piston rods and substautially adjacent to the upper ends of the cylinders 10 and 11. The shoulders 34: and guides 33 are preferably of such relative lengths that a portion of the shoulders 3 1 passes over and beyond the guides at each end of the stroke, so as to avoid localized wear spots or portions on the shoulders or guides.

A cover 35, which may also be a casting, is preferably provided for the member 18 which is preferably open at its top as shown, and since the operating parts are preferably run in a bath of oil, a tight connection between such cover and the casting 18 is preferably provided, the parts having preferably a ground or gasketed fit on one another and secured together by suitable means, such as bolts 36, 36. The bearings 37 37 for the drive shaft 28 preferably have the form of split bushings and may conveniently be provided half in the upper part of the member 18 and half in the lower por tion of the member 35, as clearly illus trated in Figures 2 and 3. The shaft 28 may project on either or both sides of the easing in order to conveniently secure driving means thereto, and, as will be apparent, it may be driven in either direction. The

opening 30 in the frame 31 is preferably elongated somewhat at the ends so as to give end clearance for the eccentric 29, as indicated in dotted lines in Figure 1, the working surface of the cam way being preferably in substantially short portions thereof at about its top and bottom portions. The working chamber in the member 18 is preferably filled with lubricating fluid, such as oil or the like, to substantially the line 38 (Fig. 1), and a filling plug 39 may be pro vided, the same also serving to limit the amount of oil which can be introduced, the oil being preferably put in the pump until it overflows at the plug opening 39. A drain plug may be provided for the oil chamber, if desired. It will be seen that all the working parts run in oil and that as the piston rods are raised to substantially the position corresponding with the dotted line position of the frame 31 shown in the upper portion of Figure 1, they will be coated with oil, and the upper ends of the bearings for such piston. rods in the bosses 23 are of course immersed in oil so that, particularly in the case of the low pressure cylinder and upon the suction stroke, more or less oil will gradually work into the pump cylinders from the oil bath in the casting 18.

The pistons are double acting, admitting and compressing air at ench end of the cylinders, and the air is compressed at each end of the low pressure cylinder, and is discharged to the opposite end of the high pressure cylinder. The air is further compressed in the high pressure cylinder. The control of the air in its passage through the pump is accomplished by six check valves arranged in the casting 12 and indicated, for identification, by Roman numerals I to V1.

Admission of air to the low pressure cylinder 10 is through the passage 10 controlled by the check valve I (Figure 7) to the upper end of such cylinder by the inlet 11. Air is admitted through the opening 4C2 formed partly in the screw-threaded plug 42 and controlled by the check valve III (Figure 9) to the lower end of such cylinder 10, which it enters by the inlet 4.3. Part of the passage 40 and the seat for the valve I are preferably formed in the casting 18 substantially as shown. but with this exception the passages and check valves are formed or located entirely within the casting 12. The inlets 40 and 42 may be formed directly in the casting wall and exposed to the outer air, but preferably they lead from the chamber a4, (Figure 5), which is formed by encircling the high pressure cylinder 11 with the cover 45 formed of sheet metal or the like, which'may be suitably secured to the walls of the casting by screws 1 :6. \Vhen such plate or cover is provided, openings such as the openings 47 are provided at a location adapted to obtain a sweep of the incoming air past the walls of the high pressure cylinder 11 and to assist in cooling the same, the heat thus imparted to the incoming air being dissipated to a considerable extent by the relatively extensive walls and surfaces of the low pressure cylinder 10, and in this way the heating up of the two cylinders in use may be equalized to a considerable ex tent, instead of being substantially or largely confined to the high pressure cylinder, as might otherwise be the case. Air may thus be finally discharged from the pump at a considerably lower temperature than would otherwise be obtainable. The cylinders or either of them may be provided with ribs or the like, if desired, to give additional exterior radiating and conducting surface.

The discharge of partially compressed air from the upper end of the low pressure cylinder 10 into the lower end of the high pressure cylinder 11 is out through the port 11 (Figure 10) past the check valve I which remains seated, downward by the passage 18 and through the check valve II which is forced from its seat, and into the lower end of the high pressure cylinder 11 through the port 4:9. The passage of partially com-- pressed air from the lower end of the low pressure cylinder 10 is through the port 43 (Figure 8) past the check valve III which remains seated, upward through the passage 50, through the check valve IV which is forced from its seat, and into the upper end of the cylinder 11 by the port 51.

The discharge of the compressed. air from the upper end of the high pressure cylinder 11 is through the port 52 (Figure 1), downward through the passage 53, through the check valve V and passage 54 into the hollow chamber 56 in the casting 12, the passage 54 being directed to discharge against the bafiie plate 57. The discharge of compressed air from thelower end of the high pressure cylinder 11 is out through the port 58 (Figure 1), through the check valve VI, through the passage 59, past the check valve V (which remains seated) and into the chamber 56 through the passage 54.

The compressed air is discharged through the port 60 on the other side'of the downwardly extending wall or baffle plate 57, through the hose connection 61 to which the flexible hose 62 is secured leading to the tire or other device into which the air is to be pum ed.

It wi 1 be seen that each end of the high pressure cylinder contains two ports, one to the air discharge and one leading in from the opposite end of the low pressure cylinder, those for the upper end of the high pressure cylinder being numbered 51 and 52 (Figures 1 and 8), and for the lower ends 49 and 58 (Figures 1 and 10). Accordingly when the back pressure in the passages leading to the hose 62 is low, as during the early stages of pumping up a tire, large volumes of air may be pumped in substantially directly by the low pressure cylinder 10, the air passing momentarily into the high pressure cylinder through passages 51 and 19, respectively, (Figures 8 and 10) and immediately out through the passages 52 and 58, respectively, (Figure 1). When the back pressure increases, however, the pressure from the cylinder 10 is no longer suliicient to open the check valves V and VI and all the air partially compressed in the low pressure cylinder is recompressed in the cylinder 11 before discharge.

The check valves are preferably all of substantially identical construction and may comprise a perforated disk 70, preferably of material such as fibre, with preferably identical longitudinally extending guide members on each side thereof and between which the disk is interposed. In the form shown, one of such members 71 has a stem 71 thereon extending through the opening 72 in the fibre disk and passing through a central longitudinal bore in the member 7 3, which is preferably substantially identical with the member 70, except for the fact of its being provided with a bore instead of the stem 71. The parts are secured together preferably by riveting over the stem 71 to form a head 7 4. Formed in this or equivalent ways, the two sides of the valve are substantially identical and the valve may be inserted interchangeably and with either of the faces of the disk 70 thereof in contact with a valve seat as 75, (Figure 11). Springs 76 are preferably provided to encircle the guide member of the valve opposite the seat, and the same are preferably received in recesses such as shown at 77. The material of the members 7 O and 73 is preferably cut away at the sides to permit the free passage of air therearound. In Figure 12 such valve members are shown provided with three arcuate cut-outs 78, whereas in the other figures of the drawings in which the check valves appear, they are shown as having cut-outs on four sides, but it will, of course, be apparent that considerable variation in this respect is possible. Check valves constructed as described operate efliciently with little noise and cannot readily stick or bind, and operate well even if the springs therefor should be broken.

It is desirable that oil be prevented from being discharged with the air, particularly into rubber tires which may be injured thereby, and means are provided for preventing the oil being carried along by the air at least to a harmful extent. In the form shown an oil well 63 is provided which is preferably substantially an extension of the chamber 56, and the air is driven around the dead wall or baffle plate 57 whereby an efiirises to an unduly great height, it will be carried over with the air discharged from the pump. In the form shown such means for discharging surplus oil is combinedwith means for testing the operation of the pump and enabling the operator to determine whether it is working well. Such means, in

the embodiment shown, takes the form of a screw drain cock clearly illustrated in Figures 2 and 3, and it will be seen that upon opening said drain cock, as by unscrewing it, the oil may be permitted-to be discharged through a suitable drainopenmg 65*, being driven out by escaping air. Since, in the case of the use of a pump on trucks for "inflating large tires, the chaufleur or mechanic has substantially nothing to do while the inflation going'on, it will be easy for him to open the drain cock 65 occasionally, which he will also be inclined to do as it affords a test for indicating how the pump is working. If such drain cock is oaened for a few seconds-in thecourse of in ation of" three or four tires, it will be ordinarily sutficient for securing the discharge of surplus oil and preventing the discharge of any substantial quantity of oil with the compressed air.

It will be seen that a compressionpump in accordance with the present invention em.- bodies numerous features of advantage. It is simply constructed and readily assembled, is compact and low down and can be at tached to operating means, such as automobile or truck engines, inconvenient fashion, the drive shatt28 being preferably made reversible so that it may project from either side. Also it may be conveniently secured in place in a variety of dlflGlGllt positions,

as, for example, by means oi'suitable fas tening bolts entering threaded holes 67, 67, provided in duplicate on opposite sides of the pump, the material whereof is preferably suitably thickened about such openings, as indicated at 68, in order to provide the necessary strength. Lubrication is cared for in an extremely efficient manner, allthe working parts being constantly run in a bath of oil, and the parts being soarranged and constructed as that the oil in said bath gradually enters the pump cylinders, keeping the same thoroughly lubricatedand excessive oil may be disposed of with ease by means of the drain cook 65 being open for a short interval, and various other advantages are secured, as will be apparent from the foregoing description. It is to be understood that the embodiment illustrated is intended only for the purpose of affording a clear understanding of my invention and that I am not to be limited thereby, but that my invention is of the scope defined bymy claims.

I claim:

1. A compound double acting compression pump comprising a combination of high and low pressure cylinders, arranged side by side in a single casting, with separate axes parallel to one another, and donble acting pistons therein with but six check valves for controlling the passage of fluid.

2. The combination in a pump of an oil separator, a pump cylinder and its piston, and an oil reservoir arrangedrespectively one above another, the reservoir being arranged to feed oil to the cylinder, and the separator being adapted to separate oil from compressed air discharged from the cylinder.

3. The combination in a pump of an oil separator, a cylinder with its piston and upwardly projecting piston rod, and an oil chamber into which the piston projects and having means for actuating the piston, the separator, cylinder and chamber being ar ranged respectively one above another and providing a relatively high device of relatively small horizontal section and adapted to be secured to and operated from an in ternal combustion engine.

4. In a pump, the combination of a cylinder, a piston and a piston rod therefor, packing means for said piston rod, a chamber above the cylinder and into which said piston rod projects, said chamber being adapted to contain an oil bath, and means enclosed within saidchamber for imparting a reciprocatory movement to said piston rod and piston.

5. In acompression pump, the combination of a cylinder, a piston therein and a piston rod projecting upwardly from the cylinder, packing means for the piston rod,

a chamber into which said piston rod projects and adapted to contain an oil bath, means enclosed in said chamber for imparting reciprocatory movement to the piston rod and piston, whereby oil is introduced into the cylinder from said chamber, and means beneath the cylinder for separating oil from compressed fluiddischarged from the pump.

6. In a compression pump, the combination of a plurality of cylinders arranged side by side and comprising a low pressure and a high pressure cylinder, pistons in said cylinders and piston rods projecting therefrom, packing means for said piston rods, said piston rods and packing means being mounted to substantially float in their bearings, a chamber above said cylinders adapted to contain an oil bath, a Scotch yoke in said chamber, a rotating cam adapted to impart reciprocatory movement to said Scotch yoke and pistons, said Scotch yoke having sine shoulder members extending low down thereon and substantially closely adjacent to the cylinders, and guideavays for said shoulders formed in the walls of said chamber.

7. In a compression pump, the combination of a cylinder, a piston therein and a piston rod projecting upwardly therefrom, packing means above said cylinder in which said piston rod is adapted to substantially float, a chamber above the cylinder into which the piston rod projects and adapted to contain an oil bath, means for imparting reciprocatory movement to said piston rod, and guide means therefor located on opposite sides of the upwardly projecting ends of the piston rod.

8. In a compression pump, the combination of a casting having an openended cy lindrical bore formed therein and provided with a piston and piston rod, a second cast ing adapted to be secured upon the first named casting and having packing means about the piston rod in its lower wall and adapted to contain an oil bath, a third casting arranged on top of the second casting, the last two named castings forming an enclosed chamber, and means in said chamber for imparting reciprocatory movement to said piston.

9. In a compression pump, the combination of three castings placed successively on top of one another and secured together, the lower casting containing cylinders and pistons moving therein, piston rods for said pistons projecting into the middle .casting, said middle casting being adapted to contain an oil bath and the top casting forming a cover therefor, and rotatable means having bearings between the second and third castings and adaptedto impart recip rocatory movement to the piston rods.

10. In a compression pump, the combination of a bottom casting having cylinder bores formed therein and open at their upper ends, pistons in said cylinders and having piston rods projecting upwardly therefrom, a second casting arranged upon the first casting and closing the open ends of the cylinders exceptthat passages are provided for the pistons having packing means therein, said casting being adapted to contain an oil bath and providing an enclosed chamber, means in said casting for imparting reciprocatory movement to said pistons, and guiding means for said movement imparting means located within the second named casting and substantially closely ad jacent to the upper ends of said cylinders.

11. In an air compression pump, the combination of a high pressure cylinder and a low pressure cylinder, and means whereby the air admitted to the low pressure cylin der is utilized to cool the high pressure cylinder.

12. In an air compression pump, the com.- hination of high pressure and low pressure cylinders, and means whereby the air admitted to a low pressure cylinder is caused to pass over the walls of a high pressure cylinder before admission to a low pressure cylinder. 7

13. In an air compression pump, the combination of high and low pressure cylinders, an enclosure about a high pressure cylinder, and means for admitting air into and through said enclosure to a low pressure cylinder, whereby the walls of the high pressure cylinder are cooled by the air admitted to the low pressure cylinder.

14. In an air compression pump, the combination of a high pressure cylinder and a low pressure cylinder, and a sheet metal covering'lor the high pressure cylinder provided with air inlet openings, the inlets of the low pressure cylinder being arranged within said shell and adapted to cause the air incoming to the low pressure cylinder to sweep past the walls of the high pressure cylinder and assist in cooling same.

15. In a compound pump comprising a low pressure cylinder and a high pressure cylinder into which air is received from the low pressure cylinder and further compressed, an oil chamber over both cylinders and into which their piston rods project, whereby oil is carried into the low pressure cylinder only on its suction stroke, said oil passing with the air into and through the high pressure cylinder, and means for separating oil from discharged air after leaving the high pressure cylinder.

16. In a compound double acting pump, the combination of a casting having high pressure and low pressure cylinders therein side by side, double acting pistons in said cylinders adapted to move together, said casting being provided with passages formed therein connecting opposite ends of the low pressure and high pressure cylinders, and check valves in said passages, an air admission passage leading into each of the first named passages, and check valves for said air admission passages.

17. In an air pump, the combination with a casting having a low pressure cylinder and a high pressure cylinder formed therein and disposed side by side, a double acting piston in each cylinder, each of said cylinders being provided at each end with a port, and passages formed substantially entirely in said casting and connecting the ports at the respective ends of the low pressure cylinder with the ports at the opposite ends of the high pressure cylinder, an air admission passage leading into each of the first named the air admission passages, and outwardly opening check valves for the first named passages.

18. In a pump a cylinder. an oil chamber thereoven a piston in the cylinder and having a piston rod extending into the body of the oil in said chamber whereby oil is carried into the cylinder by the piston rod for lubricating the same, and means for separating the oil from compressed air dis-- charged from said cylinder.

19 In a compression pump, an oil chamber, a cross head and actuating means therefor in said chamber, high and low pressure pistons on the same side of said cross head FRED s. CARVER. 

